Partial support is requested for the 36th Annual Scientific Meeting of the Gerontological Society of America. This national meeting will bring together approximately 2500-3000 educators, practitioners and researchers from biological, biomedical and psycho-social areas of gerontology. Of these, it is those who are engaged in bio-gerontological research who have the potential of providing an understanding of the basic mechanisms of the aging process. In order to serve the bio-gerontologists, the program to be presented is designed to bring both a general sense of the current status of certain important areas of research and a more narrowly focused description of the latest advances. In a few cases, non-gerontologists who are outstanding experts in appropriate fields of biochemistry have been selected to participate in the symposia. They will serve to describe recent progress and thus provide a background against which gerontological studies can be placed in context. To the degree possible, areas have been selected in which general advances or new and exciting findings have been made, with the restriction that the topics have not been, as presented here, recent subjects of other aging meetings (including Gordon Conferences). The topics encompass the following: (1) Function of organelles, membranes and structures during aging; (2) recent studies of nucleic acids in relation to aging; (3) enzymes and proteins in aging; (4) the effect of aging on hormone response; (5) cellular regulation in senescence; (6) immunology and aging; (7) pharmacodynamics in aging. Besides this core program, a substantial number of volunteered papers or posters arranged in sessions under appropriate headings will be presented. The program also is open to additional symposia. However, support is requested only for the seven sessions listed above. Abstracts of all presentations will be published in a special issue of The Gerontologist.